The term “modernity” is often introduced by means of a storyline moving from one to another of opposed terms. One thinks of Sir Henry Maine's status and contract, Ferdinand Tönnies's Gemeinschaft and Gessellschaft, and Henry Adams's Virgin and the dynamo. In such narratives, modernity comes with an increasing awareness of the fluid and apparently random nature of events characterizing modern existence (other terms, such as anomie, alienation, and disenchantment, also come to mind). Darwin's description, in chapter 4 of The Origin of Species, of the process of natural selection offers a defining instance of both change and its haphazard nature. While he doesn't use the phrase “random variation,” Darwin, as he apologetically notes at the beginning of chapter 5, uses the word “chance” repeatedly to name the occasional and sometimes critically important biological changes that he can't explain.